長ちょう周しゅう期き彗すい星せい

noun

long-period comet

Technical term in astronomy for a comet with an orbital period longer than 200 years.

• 長ちょう周しゅう期き彗すい星せいは、太たい陽よう系けいの遠とおくからやって来くる。

  Long-period comets come from the far reaches of the solar system.